The Haas Formula 1 team was "blindsided" by good results during the 2018 season and failed to see its '19 car problems early enough, according to team boss Gunther Steiner.
Haas's 2018 was its third season in F1 and it went on to finish fifth in the constructors' championship with 93 points.
It then began 2019 with a sixth place finish in the Australian Grand Prix, courtesy of Kevin Magnussen, before it then suffered a torrid season as it struggled with tyre management and car specification.
Haas dropped to ninth in the standings, its worst result since its debut in 2016, and scored just 28 points.
Steiner admits that 2018's success contributed to Haas struggling to come to terms with its problems last year.
Asked if the Bahrain Grand Prix, the second race of the season, was the first clue about Haas's tyre problems, Steiner said: "No, that's the first time it came to light that something isn't right, and we found we could not manage the tyres.
"Then we tried to work with the tyre, tried to influence the tyre from the outside, instead of going down to see if we had an aero problem because the car was good in qualifying.
"Barcelona, again we weren't sure if it worked or not, but when you get a good result you believe in it.
"Maybe by having these good results, in the beginning, we were a little bit blindsided, because having come off a season like 2018, which was very good, maybe we were a little bit overconfident - we just know it now.
"Not knowing where you are, you don't react properly, and once you really understand what it is [causing the problems] - which was summer break time - it's too late.
"After the summer break you don't think of the race track anymore, we were just too far off. So it was better to go back and focus on 2020."
Steiner says Magnussen and Romain Grosjean began expressing worries about the car around the time of the Spanish Grand Prix but acknowledges the team did not listen to them.
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"There [in Spain] the result was good," Steiner added about Barcelona, where both drivers scored points despite a clash between them.
"We saw it again in qualifying, but not in the race because in the race we had [a crash]. So we didn't figure out in the race what happened, but the car in Barcelona could have been strong.
"So maybe in Barcelona, we believed a little bit too much that the car is good everywhere. This car was good in Barcelona specifically. So at the time, the drivers said this is good.
"We were into Q3 and I think we qualified sixth or seventh there, pretty good. So how can we say this is not good?
"One of these things [is why] we thought it was maybe a little bit blinded by the 2018 results."
He added: "You know with hindsight, it's easy to say I would react differently to what happened in Barcelona.
"I would say 'guys, you need to get together here, something doesn't stack up'.
"We believed the results more than the data and the drivers."